The invention relates to asbestos products having improved physical properties and more particularly to asbestos that has been treated with a metal oxide. The process described herein is particularly suitable in connection with a procedure wherein the asbestos is dispersed in water, and the dispersion is later coagulated to form a solid body.
Methods for making asbestos products from dispersions are well known and are described in the following U.S. Pat. Nos. 2,972,221; 3,630,012; 3,738,805; 2,626,213; 3,676,038; 3,338,994; and 3,806,572.
In U.S. Pat. No. 3,806,572, for example, a method is described wherein a liquid asbestos dispersion is passed through nozzles into a coagulating bath to form a yarn, and the yarn is collected by pot spinning. The raw asbestos is first dispersed in the form of an aqueous colloid with the addition of a suitable dispersant. A particularly suitable dispersant is a surfactant, such as a fatty acid soap. The asbestos and soap solution are then mixed together to form a viscous dispersion having an asbestos content in the order of from about 0.5 to about 10 percent.
The dispersion is then fed through a plurality of nozzles into a bath containing a coagulant for the dispersant, which typically comprise bi- or trivalent soluble salts of a metal. The strands are then drawn away and ultimately fed into pot spinning device. The yarn thus produced is then cleaned and may be formed into a variety of forms, such as textiles, ropes and the like.
Asbestos products produced from a dispersion process are generally superior to products made by conventional methods, such as carding and spinning of the crude fiber. It would be desirable, however, to further improve the properties of asbestos products, especially abrasion resistance and tensile strength.